Railroad rail lubricators are well known for the purpose of applying grease to the inside flange of a railroad rail to reduce wear on both the rail and the wheels. One type of hydraulic rail lubricator disclosed in prior U.S. Pat. No. 4,334,596 employes gear pumps to discharge the lube. Other hydraulic systems are disclosed in U.S. Pat. Nos. 2,355,241 and 2,401,303; 2,349,259 and 2,428,171. Various differences and disadvantages exist in these prior systems such as the lack of simplicity of mechanical parts and the inherent cost of maintenance of the devices The problem includes getting a constant. supply of grease distributed onto the track without waste and with dependability each time the device is operated. The track lubricators available for use on the track, which, per se, do not form part of the present invention comprise electric, battery operated or solar powered devices which attach adjacent the track and are connected by conduits to the grease outlets. Such devices are sold by Portec Railway Products division, Box 38250, Pittsburgh, Pennsylvania, 15238-8250. Other devices are available on the market The present device can be used with existing track lubricators and easily mounts on the track for repeated operated by means of hydraulic fluid.